Curable composition

Abstract

To provide a curable composition capable of obtaining a cured product having high elongation and excellent heat resistance and weather resistance.SOLUTION: There is incorporated a (meth)acrylic acid ester-based polymer which has a weight average molecular weight of 5000 or more and 30000 or less and an SP value of 9.4 or more and 9.8 or less, in which the average number of the total of silyl groups (S1) represented by the formula (1): -SiX1X2X3 and silyl groups (S2) represented by the formula (2): -SiR1X4X5 in one molecule is 0.20 or more and less than 0.50 and the ratio of the number of silyl groups (S2) to the total number of silyl groups (S1) and silyl groups (S2) contained in one molecule is 0.3 or more and 1.0 or less, into a curable composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable composition, and more particularly to a moisture-curable curable composition that cures by moisture in the atmosphere or the like.

Background Art

[0002] A curable composition containing a polymer having a crosslinkable silyl group is used as a sealing material, adhesive, pressure-sensitive adhesive, paint, etc. for buildings by utilizing the fact that the crosslinkable silyl group reacts with moisture to form a crosslinked structure. For example, a curable composition mainly composed of a polyoxyalkylene-based polymer having a crosslinkable silyl group has good workability and a good balance of mechanical properties such as elongation at break and breaking strength, and is thus widely used as a building sealing material.

[0003] Building sealing materials may be used by being filled in the gaps of members that expand and contract over time, such as siding materials and metal curtain walls. For this reason, high elongation at break is required for building sealing materials. In addition, heat resistance and weather resistance are also important in order to maintain performance over a long period of time, and various studies have been made to improve these characteristics in a well-balanced manner (see, for example, Patent Documents 1 to 3).

[0004] Patent Document 1 discloses that the weather resistance of a polymer curable by moisture is improved by modifying a reactive silyl-terminated polyether with an alkoxysilyl group-containing acrylic polymer. Patent Document 2 also discloses that a sealing material composition containing a vinyl polymer obtained by continuously polymerizing a vinyl monomer at a temperature of 150 to 350°C using a polyoxyalkylene compound having a molecular weight in a specific range as a base polymer as a plasticizer can improve weather resistance, elongation, and stain resistance. Furthermore, Patent Document 3 discloses that a curable composition containing an acrylic polymer having a crosslinkable silyl group at the terminal and a polyether-based polymer having at least one crosslinkable silyl group can improve the mechanical properties of the resulting cured product.

Prior Art Documents

Patent Document

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] When applied to uses such as sealing materials and adhesives, the cured product obtained from the curable composition is required to have, in addition to high elongation at break, little decrease in elongation at break due to heat, that is, excellent heat resistance. Also, in applications such as construction applications where it is used outdoors or long-term performance maintenance is required, the cured product is also required to have excellent weather resistance.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a curable composition capable of obtaining a cured product having high elongation and excellent heat resistance and weather resistance.

Means for Solving the Problems

[0008] The present inventor has intensively studied to solve the above problems, and in a curable composition containing a (meth)acrylate polymer having a crosslinkable silyl group, the molecular weight and SP value of the (meth)acrylate polymer are within a specific range, and the type and number of crosslinkable silyl groups of the (meth)acrylate polymer are within a specific range, whereby a cured product having high elongation and excellent heat resistance and weather resistance can be obtained, and the present invention has been completed. Specifically, the following means are provided according to the present invention.

[0009] 〔1〕 Containing a (meth)acrylate polymer (A) having a crosslinkable silyl group, The above-mentioned (meth)acrylic acid ester polymer (A) has a weight average molecular weight of 5,000 or more and 30,000 or less, and the following formula (1): -SiX 1 X 2 X 3 …(1) (In formula (1), X 1 , X 2 and X 3 are each independently a hydroxyl group or a hydrolyzable group.) and a silyl group (S1) represented by the following formula (2): -SiR 1 X 4 X 5 …(2) (In formula (2), R 1 is a monovalent hydrocarbon group having 1 to 20 carbon atoms, or -OSiR 2 R 3 R 4 (However, R 2 , R 3 and R 4 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms.) and one or more hydrogen atoms may be substituted. X 4 and X 5 are each independently a hydroxyl group or a hydrolyzable group.) A curable composition in which the total average number in one molecule of the silyl group (S2) represented by the formula is 0.20 or more and less than 0.50, the ratio of the number of the silyl group (S2) to the total number of the silyl group (S1) and the silyl group (S2) in one molecule is 0.3 or more and 1.0 or less, and the SP value is 9.4 or more and 9.8 or less. [2] The (meth)acrylic acid ester polymer (A) contains a structural unit derived from an acrylic acid ester compound (a) in which the residue excluding -COO- in the ester group is linear or branched with 1 to 4 carbon atoms, and a structural unit derived from an acrylic acid ester compound (b) in which the residue excluding -COO- in the ester group is linear or branched with 8 to 22 carbon atoms, and optionally contains a structural unit derived from a methacrylic acid ester compound (c) in which the residue excluding -COO- in the ester group is linear or branched with 1 to 4 carbon atoms. The ratio of the structural unit derived from the acrylic acid ester compound (a) is 50% by mass or more and 95% by mass or less, the ratio of the structural unit derived from the acrylic acid ester compound (b) is 10% by mass or more and 40% by mass or less, and the ratio of the structural unit derived from the methacrylic acid ester compound (c) is 0% by mass or more and 10% by mass or less, based on the total amount of the structural units derived from the monomers constituting the (meth)acrylic acid ester polymer (A). The curable composition according to [1] above. [3] The curable composition according to [1] or [2] above, wherein the viscosity of the (meth)acrylic acid ester polymer (A) measured at 25 °C with an E-type viscometer is 1 Pa·s or more and 20 Pa·s or less. [4] The curable composition according to any one of [1] to [3] above, further containing a polyoxyalkylene polymer having a crosslinkable silyl group. [5] The curable composition according to any one of [1] to [4] above, wherein the glass transition temperature of the (meth)acrylic acid ester polymer (A) is -15 °C or lower. [6] The curable composition according to any one of [1] to [5] above, which is for a sealing material. [Advantages of the Invention]

[0010] According to the present invention, a cured product having high elongation and excellent heat resistance and weather resistance can be obtained. [Embodiments for Carrying Out the Invention]

[0011] The present invention will be described in detail below. In this specification, "(meth)acryl" means acrylic and / or methacrylic. "(meth)acrylate" means acrylate and / or methacrylate.

[0012] ≪Curable Composition≫ The curable composition of the present invention (hereinafter also referred to as "the present composition") contains a (meth)acrylic acid ester polymer having a crosslinkable silyl group and having a weight average molecular weight and an SP value within specific ranges respectively (hereinafter also referred to as "(meth)acrylic acid ester polymer (A)"). Hereinafter, the components contained in the present composition and optional components (hereinafter also referred to as "other components") blended as necessary will be described.

[0013] <(Meth)acrylic Acid Ester Polymer (A)> (Meth)acrylic acid ester polymer (A) has a hydroxyl group or a hydrolyzable group on a silicon atom and has a silicon-containing group (hereinafter also referred to as "crosslinkable silyl group") capable of forming a siloxane bond. Examples of the crosslinkable silyl group include a group represented by the following formula (1) (hereinafter also referred to as "silyl group (S1)") and a group represented by the following formula (2) (hereinafter also referred to as "silyl group (S2)"). (Meth)acrylic acid ester polymer (A) has both silyl group (S1) and silyl group (S2) as crosslinkable silyl groups, or has no silyl group (S1) and has silyl group (S2). -SiX 1 X 2 X 3 …(1) (In formula (1), X 1 , X 2 and X 3 are each independently a hydroxyl group or a hydrolyzable group.) -SiR 1 X 4 X 5 …(2) (In formula (2), R 1 is a monovalent hydrocarbon group having 1 to 20 carbon atoms or -OSiR 2 R 3 R 4 (wherein R2 , R 3 and R 4 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms. ), and one or more hydrogen atoms may be substituted. X 4 and X 5 are each independently a hydroxyl group or a hydrolyzable group. )

[0014] ·Regarding the silyl group (S1) In the above formula (1), examples of the hydrolyzable group include a hydrogen atom, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), an alkoxy group, an alkenyloxy group, a cycloalkoxy group, an aryloxy group, an acyloxy group, an amino group, an acid amide group, an aminooxy group, a thiol group, etc. The hydrolyzable group in the above formula (1) is preferably a halogen atom, an alkoxy group, an alkenyloxy group or an acyloxy group in terms of high activity, and an alkoxy group is more preferable in terms of easy control of reactivity, ensuring storage stability, and high versatility. Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, etc.

[0015] Specific examples of the silyl group (S1) include a trimethoxysilyl group, a triethoxysilyl group, a triisopropoxysilyl group, a tris(2-propenyloxy)silyl group, etc. Among these, the trimethoxysilyl group is preferable for the silyl group (S1) in terms of high reactivity, and the triethoxysilyl group is preferable in terms of showing good reactivity and high storage stability.

[0016] ·Regarding the silyl group (S2) In the above formula (2), examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, etc. When one or more hydrogen atoms of the monovalent hydrocarbon group having 1 to 20 carbon atoms are substituted, examples of the substituent include a halogen atom, an alkoxy group, etc. Specific examples and preferred examples of the hydrolyzable group include the same groups as those exemplified in the description of the silyl group (S1).

[0017] Specific examples of the silyl group (S2) include methyldimethoxysilyl group, diethoxymethylsilyl group, ethyldiethoxysilyl group, diisopropoxymethylsilyl group, (chloromethyl)dimethoxysilyl group, (ethoxymethyl)dimethoxysilyl group, and the like. Among these, the dimethoxymethylsilyl group is preferred in terms of higher reactivity of the silyl group (S2), and the diethoxymethylsilyl group and the ethyldiethoxysilyl group are preferred in terms of high reactivity and high storage stability.

[0018] The positions of the silyl group (S1) and the silyl group (S2) in the (meth)acrylate polymer (A) are not particularly limited. That is, the (meth)acrylate polymer (A) may have the silyl group (S1) at the polymer terminal, on the side chain, or both at the polymer terminal and on the side chain. Similarly, the (meth)acrylate polymer (A) may have the silyl group (S2) at the polymer terminal, on the side chain, or both at the polymer terminal and on the side chain. In terms of improving the tensile properties and rubber elasticity of the cured product and the ease of introducing the crosslinkable silyl group, the (meth)acrylate polymer (A) preferably has the silyl group (S1) and the silyl group (S2) at least on the side chain.

[0019] The (meth)acrylate polymer (A) satisfies the following requirements 1, 2, 3, and 4. (Requirement 1) The weight average molecular weight is 5,000 or more and 30,000 or less. (Requirement 2) The total average number of the silyl group (S1) and the silyl group (S2) contained in one molecule is 0.20 or more and less than 0.50. (Requirement 3) The ratio of the number of the silyl group (S2) to the total number of the silyl group (S1) and the silyl group (S2) contained in one molecule is 0.3 or more and 1.0 or less. (Requirement 4) The SP value is 9.4 or more and 9.8 or less. Hereinafter, each requirement will be described in order.

[0020] ·Regarding Requirement 1 (Meta)acrylic acid ester polymer (A) has a weight average molecular weight (Mw) of 5,000 or more and 30,000 or less. When the Mw of (meta)acrylic acid ester polymer (A) is less than 5,000, the mechanical properties and weather resistance of the cured product tend to be insufficient. Further, when the Mw of (meta)acrylic acid ester polymer (A) exceeds 30,000, the fluidity and coatability of the curable composition decrease, or the elongation of the cured product decreases. Also, the decrease in the elongation of the cured product due to heat is large, and there is a tendency to be inferior in heat resistance.

[0021] From the viewpoint of obtaining a cured product exhibiting good mechanical properties and weather resistance, the Mw of (meta)acrylic acid ester polymer (A) is preferably 5,500 or more, more preferably 6,000 or more, still more preferably 6,500 or more, and even more preferably 7,000 or more. Further, from the viewpoint of obtaining a cured product having high elongation and excellent heat resistance, the Mw of (meta)acrylic acid ester polymer (A) is preferably 25,000 or less, more preferably 22,000 or less, still more preferably 20,000 or less, and even more preferably 18,000 or less.

[0022] (Meta)acrylic acid ester polymer (A) preferably has a number average molecular weight (Mn) in the range of 1,000 or more and 20,000 or less. When the Mn of (meta)acrylic acid ester polymer (A) is 1,000 or more, when a cured product is produced using (meta)acrylic acid ester polymer (A), the mechanical properties and durability of the cured product can be sufficiently high. Further, when the Mn of (meta)acrylic acid ester polymer (A) is 20,000 or less, good fluidity and coatability can be ensured. From the above viewpoints, the Mn of (meta)acrylic acid ester polymer (A) is more preferably 1,500 or more, still more preferably 2,000 or more, and even more preferably 2,500 or more. Also, the Mn of (meta)acrylic acid ester polymer (A) is more preferably 18,000 or less, still more preferably 15,000 or less, and even more preferably 12,000 or less.

[0023] Incidentally, the Mw and Mn of the (meth)acrylate polymer (A) are values in terms of polystyrene measured by gel permeation chromatography (GPC). Details of the measurement method follow the method described in the examples below.

[0024] Regarding the (meth)acrylate polymer (A), the molecular weight distribution (Mw / Mn), represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), is preferably 6.0 or less from the viewpoint of obtaining a cured product exhibiting good heat resistance and weather resistance. The molecular weight distribution of the (meth)acrylate polymer (A) is more preferably 5.5 or less, still more preferably 5.0 or less, yet more preferably 4.5 or less, and even more preferably 4.0 or less. The lower limit of the (meth)acrylate polymer (A) is not particularly limited, but is, for example, 1.1 or more from the viewpoint of ease of production.

[0025] ·Regarding Requirement 2

[0026] In the (meth)acrylate polymer (A), the total number of silyl groups (S1) and silyl groups (S2) in one molecule (hereinafter, also referred to as "the number of crosslinkable silyl groups f(Si)") is on average 0.20 or more and less than 0.50. When the number of crosslinkable silyl groups f(Si) is less than 0.20, a crosslinked structure is not sufficiently formed when producing a cured product from the curable composition, and as a result, the heat resistance and weather resistance of the cured product tend to be inferior. Further, when the number of crosslinkable silyl groups f(Si) is 0.50 or more, the crosslinking reaction easily proceeds over time via unreacted crosslinkable silyl groups remaining in the cured product, easily leading to a decrease in the elongation and weather resistance of the cured product.

[0027] Note that crosslinkable silyl groups such as silyl group (S1) and silyl group (S2) can be regarded as having one reactive point as a whole. Therefore, in the present invention, the entire crosslinkable silyl group is regarded as one crosslinkable functional group. For example, 3-methacryloxypropyltrimethoxysilane is a compound having a trimethoxysilyl group as a crosslinkable silyl group, and the number of crosslinkable silyl groups in one molecule is one. Further, 3-methacryloxypropylmethyldimethoxysilane is a compound having a methyldimethoxysilyl group as a crosslinkable silyl group, and the number of crosslinkable silyl groups in one molecule is one.

[0028] From the viewpoint of obtaining a cured product excellent in heat resistance and weather resistance, the number of crosslinkable silyl groups f(Si) of the (meth)acrylate polymer (A) is preferably 0.23 or more, more preferably 0.25 or more, still more preferably 0.28 or more, and even more preferably 0.30 or more. From the same viewpoint, the number of crosslinkable silyl groups f(Si) is preferably 0.47 or less, more preferably 0.45 or less.

[0029] Note that the number of crosslinkable silyl groups f(Si) can be calculated, for example, when a monomer having a silyl group (S1) and / or a monomer having a silyl group (S2) is used in the synthesis of the (meth)acrylate polymer (A), by calculating the molar fraction of the total amount of the monomer having a silyl group (S1) and the monomer having a silyl group (S2) among all the monomers used in the synthesis of the (meth)acrylate polymer (A), and then multiplying the obtained molar fraction by the number average molecular weight (Mn) obtained by GPC measurement.

[0030] ·Regarding Requirement 3 (Meth)acrylic acid ester polymer (A) has a ratio of the number of silyl groups (S2) to the total number of silyl groups (S1) and silyl groups (S2) contained in one molecule (hereinafter also referred to as "crosslinkable silyl group ratio") of 0.3 or more and 1.0 or less. Specifically, when the total number of silyl groups (S1) and silyl groups (S2) in one molecule of (meth)acrylic acid ester polymer (A) is represented by f(Si), and the number of silyl groups (S2) in one molecule of (meth)acrylic acid ester polymer (A) is represented by f(S2), the crosslinkable silyl group ratio is represented by the following formula (3). Crosslinkable silyl group ratio = f(S2) / f(Si) …(3)

[0031] When the crosslinkable silyl group ratio is less than 0.3, the number of unreacted hydroxyl groups or hydrolyzable groups bonded to the crosslinkable silyl groups in the cured product increases, and the crosslinking reaction further proceeds through the crosslinkable silyl groups, resulting in an increase in the crosslink density of the cured product. Therefore, it is likely to cause a decrease in heat resistance (specifically, a decrease in elongation due to heat) and a decrease in weather resistance. From the above viewpoints, the crosslinkable silyl group ratio is preferably 0.32 or more, more preferably 0.35 or more, still more preferably 0.40 or more, even more preferably 0.45 or more, and particularly preferably 0.50 or more. Also, the crosslinkable silyl group ratio is preferably 0.95 or less, more preferably 0.90 or less.

[0032] Regarding the method for calculating the crosslinkable silyl group ratio, taking the case where a monomer having a silyl group (S1) and / or a monomer having a silyl group (S2) is used in the synthesis of (meth)acrylic acid ester polymer (A) as an example, the method for calculating the number of crosslinkable silyl groups f(Si) used in the calculation of the crosslinkable silyl group ratio is as described in Requirement 2. The number of silyl groups (S2) in one molecule of (meth)acrylic acid ester polymer (A), f(S2), can be calculated by calculating the molar fraction of the monomer having a silyl group (S2) among all the monomers used in the synthesis of (meth)acrylic acid ester polymer (A), and then multiplying the obtained molar fraction by the number average molecular weight (Mn) obtained by GPC measurement.

[0033] ·Regarding Requirement 4 (Meth)acrylic acid ester polymer (A) has an SP value of 9.4 or more and 9.8 or less. When the SP value of (meth)acrylic acid ester polymer (A) is less than 9.4 or more than 9.8, when the curable composition contains components other than (meth)acrylic acid ester polymer (A) (hereinafter, also referred to as "other components"), the compatibility with other components becomes insufficient, and as a result, the elongation and weather resistance of the cured product may become insufficient. From the viewpoint of obtaining a cured product having high elongation and good weather resistance, the SP value of (meth)acrylic acid ester polymer (A) is preferably 9.45 or more, more preferably 9.50 or more, still more preferably 9.55 or more, and even more preferably 9.60 or more. Also, the SP value of (meth)acrylic acid ester polymer (A) is preferably 9.79 or less, more preferably 9.78 or less. In the present specification, the SP value of (meth)acrylic acid ester polymer (A) is a value calculated by the Fedors method (unit: [cal / cm 3 1 / 2 ) and the value calculated from the structural units excluding the monomer having a crosslinkable silyl group is used as the SP value of (meth)acrylic acid ester polymer (A).

[0034] (Meth)acrylic acid ester polymer (A) only needs to satisfy the above Requirements 1 to 4, but further, it is preferable that the following physical property values are within a specific range.

[0035] ·Glass transition temperature ​The glass transition temperature (Tg) of the (meth)acrylic acid ester polymer (A) is preferably -15°C or lower. When the Tg of the (meth)acrylic acid ester polymer (A) is -15°C or lower, the viscosity at room temperature (25°C) does not become too high, ensuring workability, and a cured product with good weather resistance can be obtained. From these viewpoints, the Tg of the (meth)acrylic acid ester polymer (A) is more preferably -25°C or lower, still more preferably -30°C or lower, even more preferably -35°C or lower, yet more preferably -40°C or lower, still more preferably -45°C or lower, and particularly preferably -50°C or lower. There is no particular limitation on the lower limit of the Tg of the (meth)acrylic acid ester polymer (A), but for example, it is -80°C or higher, preferably -75°C or higher.

[0036] In addition, in this specification, the calculation method of the Tg of the (meth)acrylic acid ester polymer (A) is according to the following mathematical formula (4). Here, Tg is the glass transition temperature (K) of the copolymer, Tga, Tgb, Tgc, etc. are the glass transition temperatures (K) of the homopolymers of the respective monomers a, b, c, etc., and Wa, Wb, Wc, etc. represent the weight fractions of the respective monomers a, b, c in the copolymer. Also, the glass transition temperature (K) of the homopolymer is the value described in Polymer Handbook (4th Edition, edited by J. Brandrup and E. H. Immergut, Interscience Publishers). However, the value calculated from the structural units excluding the monomer having a crosslinkable silyl group is used as the Tg of the (meth)acrylic acid ester polymer (A). 1 / Tg = (Wa / Tga) + (Wb / Tgb) + (Wc / Tgc) + … (4)

[0037] · Viscosity Regarding the viscosity of the (meth)acrylate polymer (A), the viscosity measured at 25°C using an E-type viscometer (hereinafter also referred to as "E-type viscosity") is preferably 1 Pa·s or more and 20 Pa·s or less. When the E-type viscosity of the (meth)acrylate polymer (A) is within the above range, a curable composition capable of obtaining a cured product having good fluidity and coatability, and being highly strong and excellent in heat resistance can be obtained. The E-type viscosity of the (meth)acrylate polymer (A) is preferably 2 Pa·s or more, more preferably 4 Pa·s or more, and still more preferably 5 Pa·s or more in terms of being able to suppress liquid spreading and obtaining a cured product having sufficiently high strength and heat resistance. Regarding the upper limit of the E-type viscosity of the (meth)acrylate polymer (A), from the viewpoint of ensuring the fluidity and coatability of the curable composition, it is more preferably 19 Pa·s or less, still more preferably 18 Pa·s or less, and even more preferably 15 Pa·s or less. Details of the method for measuring the E-type viscosity in the (meth)acrylate polymer (A) follow the method described in the examples below.

[0038] ·Synthesis of (meth)acrylate polymer (A) The method for obtaining the (meth)acrylate polymer (A) is not particularly limited. Examples of the synthesis method of the (meth)acrylate polymer (A) include the following methods (I) to (IV). (I) A method of polymerizing a monomer mixture containing a (meth)acrylate compound and a vinyl compound containing a crosslinkable silyl group. (II) A method of polymerizing a monomer mixture containing a (meth)acrylate compound and an unsaturated carboxylic acid, and introducing a crosslinkable silyl group into the polymer side chain by an addition reaction between the carboxyl group-containing polymer obtained by the polymerization and a crosslinkable silyl group-containing epoxy compound. (III) A method of polymerizing a monomer mixture containing a (meth)acrylate compound and a vinyl compound containing an epoxy group, and introducing a crosslinkable silyl group into the polymer side chain by an addition reaction between the epoxy group-containing polymer obtained by the polymerization and a crosslinkable silyl group-containing amine compound. (IV) A method for introducing a crosslinkable silyl group at the polymer terminal by polymerizing a monomer mixture containing a (meth)acrylic acid ester compound in the presence of a polymerization regulator such as a RAFT agent having a crosslinkable silyl group.

[0039] Among the above, the method (I), that is, the method of copolymerizing a (meth)acrylic acid ester compound and a vinyl compound containing a crosslinkable silyl group, is preferable in that a crosslinkable silyl group can be easily introduced and a cured product having good elongation at break, breaking strength, and weather resistance can be obtained.

[0040] The monomers constituting the (meth)acrylic acid ester polymer (A) are not particularly limited as long as the (meth)acrylic acid ester polymer (A) contains a structural unit derived from a (meth)acrylic acid ester compound and has a crosslinkable silyl group. Examples of the monomers constituting the (meth)acrylic acid ester polymer (A) include (meth)acrylic acid ester compounds, vinyl compounds containing crosslinkable silyl groups, and monomers different from (meth)acrylic acid ester compounds and vinyl compounds containing crosslinkable silyl groups (hereinafter also referred to as "other monomers").

[0041] ·(meth)acrylic acid ester compound From the viewpoint of obtaining a cured product having high elongation and excellent heat resistance, the (meth)acrylic acid ester polymer (A) preferably contains a structural unit derived from an acrylic acid ester compound (a) in which the residue excluding -COO- in the ester group is linear or branched and has 1 to 4 carbon atoms, and a structural unit derived from an acrylic acid ester compound (b) in which the residue excluding -COO- in the ester group is linear or branched and has 8 to 22 carbon atoms, and optionally contains a structural unit derived from a methacrylic acid ester compound (c) in which the residue excluding -COO- in the ester group is linear or branched and has 1 to 4 carbon atoms as a structural unit derived from a (meth)acrylic acid ester compound.

[0042] The acrylic ester compound (a) is introduced into the (meth)acrylic ester polymer (A) as a structural unit that enhances the fluidity of the present composition while ensuring the heat resistance and weather resistance of the cured product. Specific examples of the acrylic ester compound (a) include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, and tert-butyl acrylate. From the viewpoint of sufficiently lowering the glass transition temperature of the (meth)acrylic ester polymer (A) to obtain a curable composition excellent in fluidity, in the acrylic ester compound (a), the residue excluding -COO- in the ester group is preferably linear or branched with 2 to 4 carbon atoms, and more preferably linear or branched with 4 carbon atoms.

[0043] When preparing a curable composition containing the (meth)acrylic ester polymer (A) and blending another polymer (for example, a polyoxyalkylene polymer) with the composition, considering enhancing the compatibility with the other polymer, the (meth)acrylic ester polymer (A) preferably contains a structural unit derived from the acrylic ester compound (b). Specific examples of the acrylic ester compound (b) include 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, n-nonyl acrylate, isononyl acrylate, decyl acrylate, dodecyl acrylate, tridecyl acrylate, tetradecyl acrylate, pentadecyl acrylate, hexadecyl acrylate, heptadecyl acrylate, octadecyl acrylate, nonadecyl acrylate, icosyl acrylate, and the like. From the viewpoints of the compatibility between the (meth)acrylic ester polymer (A) and the other polymer and obtaining a cured product excellent in weather resistance, in the acrylic ester compound (b), the residue excluding -COO- in the ester group is preferably linear or branched with 8 to 20 carbon atoms, and more preferably linear or branched with 8 to 18 carbon atoms.

[0044] When synthesizing the (meth)acrylate polymer (A), a methacrylate compound (c) may be used for the purpose of adjusting the glass transition temperature of the (meth)acrylate polymer (A) or the like. Specific examples of the methacrylate compound (c) include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and tert-butyl methacrylate.

[0045] In the (meth)acrylate polymer (A), the proportion of the structural unit derived from the acrylate compound (a) is preferably 50% by mass or more and 95% by mass or less with respect to the total amount of the structural units derived from the monomers constituting the (meth)acrylate polymer (A). By setting the proportion of the structural unit derived from the acrylate compound (a) within the above range, while enhancing the compatibility between the (meth)acrylate polymer (A) and other polymers, the fluidity of the present composition can be enhanced. From such a viewpoint, the proportion of the structural unit derived from the acrylate compound (a) is more preferably 60% by mass or more, still more preferably 65% by mass or more, and even more preferably 70% by mass or more with respect to the total amount of the structural units derived from the monomers constituting the (meth)acrylate polymer (A). Note that the acrylate compound (a) constituting the (meth)acrylate polymer (A) may be only one kind or two or more kinds.

[0046] Further, the proportion of the structural unit derived from the acrylate compound (b) is preferably 10% by mass or more and 40% by mass or less based on the total amount of the structural units derived from the monomers constituting the (meth)acrylate polymer (A). By setting the proportion of the structural unit derived from the acrylate compound (b) within the above range, the compatibility between the (meth)acrylate compound (A) and other polymers can be further enhanced. From this viewpoint, the proportion of the structural unit derived from the acrylate compound (b) is more preferably 12% by mass or more, and still more preferably 15% by mass or more, based on the total amount of the structural units derived from the monomers constituting the (meth)acrylate polymer (A). Also, the proportion of the structural unit derived from the acrylate compound (b) is more preferably 40% by mass or less, still more preferably 30% by mass or less, and even more preferably 25% by mass, based on the total amount of the structural units derived from the monomers constituting the (meth)acrylate polymer (A). Note that the acrylate compound (b) constituting the (meth)acrylate polymer (A) may be only one kind or two or more kinds.

[0047] In the (meth)acrylate polymer (A), the proportion of the structural unit derived from the methacrylate compound (c) is preferably 0% by mass or more and 10% by mass or less based on the total amount of the structural units derived from the monomers constituting the (meth)acrylate polymer (A). By setting the proportion of the structural unit derived from the methacrylate compound (c) within the above range, it becomes easier to ensure the fluidity of the present composition. From this viewpoint, the proportion of the structural unit derived from the methacrylate compound (c) is more preferably 8% by mass or less, and still more preferably 5% by mass or less, based on the total amount of the structural units derived from the monomers constituting the (meth)acrylate polymer (A). Note that the methacrylate compound (c) constituting the (meth)acrylate polymer (A) may be only one kind or two or more kinds.

[0048] From the viewpoint of enhancing the fluidity of the composition and obtaining a cured product excellent in weather resistance and heat resistance, the proportion of the structural units derived from the (meth)acrylic acid alkyl ester compound (preferably, the total of the acrylic acid ester compound (a), the acrylic acid ester compound (b), and the methacrylic acid ester compound (c)) in the (meth)acrylic acid ester polymer (A) is preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more, based on the total amount of the structural units derived from the monomers constituting the (meth)acrylic acid ester polymer (A).

[0049] In addition, within a range not impairing the effects of the present invention, as the (meth)acrylic acid ester compound constituting the (meth)acrylic acid ester polymer (A), a compound different from the acrylic acid ester compound (a), the acrylic acid ester compound (b), and the methacrylic acid ester compound (c) (hereinafter, also referred to as "other (meth)acrylic acid ester compound") may be used in combination. Specific examples of the other (meth)acrylic acid ester compound include acrylic acid alkyl esters having 5 to 7 carbon atoms, methacrylic acid alkyl esters having 5 to 22 carbon atoms, (meth)acrylic acid alkoxyalkyl ester compounds, (meth)acrylic acid ester compounds having a polyoxyalkylene structure, unsaturated carboxylic acids, unsaturated acid anhydrides, hydroxy group-containing (meth)acrylic acid ester compounds, epoxy group-containing (meth)acrylic acid ester compounds, amino group-containing (meth)acrylic acid ester compounds, aliphatic cyclic ester compounds of (meth)acrylic acid, and aromatic ester compounds of (meth)acrylic acid, and the like.

[0050] Specific examples of the alkyl acrylate having 5 to 7 carbon atoms and the alkyl methacrylate having 5 to 22 carbon atoms include hexyl (meth)acrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, n-nonyl methacrylate, isononyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, pentadecyl methacrylate, hexadecyl methacrylate, heptadecyl methacrylate, octadecyl methacrylate, nonadecyl methacrylate, icosyl methacrylate, and the like.

[0051] Specific examples of the alkoxyalkyl (meth)acrylate compound include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, n-propoxyethyl (meth)acrylate, n-butoxyethyl (meth)acrylate, methoxypropyl (meth)acrylate, ethoxypropyl (meth)acrylate, n-propoxypropyl (meth)acrylate, n-butoxypropyl (meth)acrylate, methoxybutyl (meth)acrylate, ethoxybutyl (meth)acrylate, n-propoxybutyl (meth)acrylate, and n-butoxybutyl (meth)acrylate.

[0052] Specific examples of the (meth)acrylate compound having a polyoxyalkylene structure include polyoxyethylene (meth)acrylate, polyoxypropylene (meth)acrylate, polyoxybutylene (meth)acrylate, polyoxyethylene-polyoxypropylene (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, lauroxypolyethylene glycol (meth)acrylate, stearoxypolyethylene glycol (meth)acrylate, octoxypolyethylene glycol polypropylene glycol (meth)acrylate, nonylphenoxypolypropylene glycol (meth)acrylate, and phenoxypolyethylene glycol polypropylene glycol (meth)acrylate.

[0053] Examples of the unsaturated carboxylic acid include (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, cinnamic acid, and further include monoalkyl esters of unsaturated dicarboxylic acids (such as monoalkyl esters of maleic acid, fumaric acid, itaconic acid, citraconic acid, etc.). Examples of the unsaturated acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride, etc.

[0054] Examples of the hydroxy group-containing (meth)acrylic acid ester compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and mono(meth)acrylic acid esters of polyalkylene glycols (such as polyethylene glycol, polypropylene glycol, etc.).

[0055] Examples of the epoxy group-containing (meth)acrylic acid ester compound include glycidyl (meth)acrylate, glycidyl ether of 4-hydroxybutyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, etc.

[0056] Examples of the amino group-containing (meth)acrylic acid ester compound include dimethylaminomethyl (meth)acrylate, diethylaminomethyl (meth)acrylate, 2-dimethylaminoethyl (meth)acrylate, 2-diethylaminoethyl (meth)acrylate, 2-(di-n-propylamino)ethyl (meth)acrylate, 2-dimethylaminopropyl (meth)acrylate, 2-diethylaminopropyl (meth)acrylate, 2-(di-n-propylamino)propyl (meth)acrylate, 3-dimethylaminopropyl (meth)acrylate, 3-diethylaminopropyl (meth)acrylate, 3-(di-n-propylamino)propyl (meth)acrylate, etc.

[0057] Specific examples of the aliphatic cyclic ester compound of (meth)acrylic acid include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and the like.

[0058] Specific examples of the aromatic ester compound of (meth)acrylic acid include phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxymethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 3-phenoxypropyl (meth)acrylate, and the like.

[0059] In the (meth)acrylic acid ester polymer (A), the proportion of the structural unit derived from other (meth)acrylic acid ester compounds (the total amount in the case of two or more kinds) is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, based on the total amount of the structural units derived from the monomers constituting the (meth)acrylic acid ester polymer (A), from the viewpoint of obtaining a cured product having high elongation and excellent heat resistance and weather resistance.

[0060] · Vinyl compound containing a crosslinkable silyl group When synthesizing the (meth)acrylic acid ester polymer (A) and copolymerizing a vinyl compound containing a crosslinkable silyl group, the vinyl compound containing a crosslinkable silyl group is not particularly limited as long as it can copolymerize with the (meth)acrylic acid ester compound. Since the vinyl compound containing a crosslinkable silyl group forms a crosslinked structure by dehydration condensation of the crosslinkable silyl groups, it is suitable as a structural unit constituting the (meth)acrylic acid ester polymer (A) in terms of efficiently performing the polymerization reaction during the production of the (meth)acrylic acid ester polymer (A) and the subsequent crosslinking reaction.

[0061] Specific examples of the crosslinkable silyl group-containing vinyl compound include vinyl compounds having a silyl group (S1), such as vinyl silanes like vinyltrimethoxysilane and vinyltriethoxysilane; alkoxysilyl group-containing (meth)acrylic acid esters such as trimethoxysilylpropyl (meth)acrylate and triethoxysilylpropyl (meth)acrylate; alkoxysilyl group-containing vinyl ethers such as trimethoxysilylpropyl vinyl ether; alkoxysilyl group-containing vinyl esters such as vinyl trimethoxysilylundecanoate; and the like.

[0062] Specific examples of the vinyl compound having a silyl group (S2) include vinyl silanes such as vinylmethyldimethoxysilane and vinyldimethylmethoxysilane; alkoxysilyl group-containing (meth)acrylic acid esters such as methyldimethoxysilylpropyl (meth)acrylate and dimethylmethoxysilylpropyl (meth)acrylate; and the like.

[0063] When synthesizing the (meth)acrylic acid ester polymer (A), the amount of the crosslinkable silyl group-containing vinyl compound used may be appropriately set so as to satisfy the above requirements 2 and 3. Specifically, the amount of the vinyl compound having a silyl group (S1) used is preferably 0% by mass or more and 3% by mass or less, more preferably 0% by mass or more and 2% by mass or less, based on the total amount of the monomers used in the synthesis of the (meth)acrylic acid ester polymer (A). Also, the amount of the vinyl compound having a silyl group (S2) used is preferably 0.3% by mass or more and 3% by mass or less, more preferably 0.5% by mass or more and 2% by mass or less, based on the total amount of the monomers used in the synthesis of the (meth)acrylic acid ester polymer (A). Note that the crosslinkable silyl group-containing vinyl compound constituting the (meth)acrylic acid ester polymer (A) may be only one kind or two or more kinds.

[0064] · Other monomers Other monomers may be any monomers copolymerizable with the (meth)acrylate compound and are not particularly limited. Examples of other monomers include styrene compounds, maleimide compounds, amide group-containing vinyl compounds, nitrile group-containing vinyl compounds, and the like. Note that the other monomers constituting the (meth)acrylate polymer (A) may be one kind or two or more kinds.

[0065] Specific examples of the styrene compound include styrene, α-methylstyrene, β-methylstyrene, vinylxylene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, p-n-butylstyrene, p-isobutylstyrene, p-t-butylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, p-isopropenylphenol, m-isopropenylphenol, o-isopropenylphenol, o-vinylbenzoic acid, m-vinylbenzoic acid, p-vinylbenzoic acid, divinylbenzene, vinylnaphthalene, and the like.

[0066] Specific examples of the maleimide compound include maleimide and N-substituted maleimide compounds. Examples of the N-substituted maleimide compounds include N-alkyl-substituted maleimide compounds such as N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-isopropylmaleimide, N-n-butylmaleimide, N-isobutylmaleimide, N-tert-butylmaleimide, N-pentylmaleimide, N-hexylmaleimide, N-heptylmaleimide, N-octylmaleimide, N-laurylmaleimide, and N-stearylmaleimide; N-cycloalkyl-substituted maleimide compounds such as N-cyclopentylmaleimide and N-cyclohexylmaleimide; N-aryl-substituted maleimide compounds such as N-phenylmaleimide, N-(4-hydroxyphenyl)maleimide, N-(4-acetylphenyl)maleimide, N-(4-methoxyphenyl)maleimide, N-(4-ethoxyphenyl)maleimide, N-(4-chlorophenyl)maleimide, N-(4-bromophenyl)maleimide, and N-benzylmaleimide, etc.

[0067] Examples of the amide group-containing vinyl compound include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N-methylol(meth)acrylamide, etc.

[0068] Examples of the nitrile group-containing vinyl compound include cyanomethyl (meth)acrylate, 1-cyanoethyl (meth)acrylate, 2-cyanoethyl (meth)acrylate, 1-cyanopropyl (meth)acrylate, 2-cyanopropyl (meth)acrylate, 3-cyanopropyl (meth)acrylate, 4-cyanobutyl (meth)acrylate, 6-cyanohexyl (meth)acrylate, 2-ethyl-6-cyanohexyl (meth)acrylate, 8-cyanooctyl (meth)acrylate, acrylonitrile, methacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-chloroacrylonitrile, α-fluoroacrylonitrile, etc.

[0069] In the (meth)acrylic acid ester polymer (A), the proportion of structural units derived from other monomers (the total amount in the case of two or more types) is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, based on the total amount of structural units derived from the monomers constituting the (meth)acrylic acid ester polymer (A).

[0070] The polymerization method for producing the (meth)acrylic acid ester polymer (A) is not particularly limited. The (meth)acrylic acid ester polymer (A) can be obtained, for example, by polymerizing monomers using known radical polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization. Among these, the solution polymerization method is preferred in terms of easy control of the molecular weight and structure of the polymer.

[0071] In the case of the solution polymerization method, for example, a target polymer can be obtained by charging a polymerization solvent and monomers into a reactor, adding a polymerization initiator, and performing polymerization. When performing the polymerization, the charging method of each raw material containing the monomers may be a batch-type initial one-shot charging in which all the raw materials are charged at once, a semi-continuous charging in which at least a part of the raw materials is continuously supplied into the reactor, or a continuous polymerization method in which all the raw materials are continuously supplied and the produced resin is continuously withdrawn from the reactor at the same time.

[0072] As an example of a preferred polymerization method for obtaining the (meth)acrylic acid ester polymer (A), while supplying a raw material containing a monomer, a polymerization solvent, and a polymerization initiator to a pressurized reactor at a constant supply rate, polymerization is carried out while heating the raw material to a high temperature, and a polymer solution in an amount corresponding to the supply amount of the raw material is withdrawn from the reactor. This is the high-temperature continuous polymerization method. According to this polymerization method, a (meth)acrylic acid ester polymer having a low molecular weight and a low viscosity can be obtained. Further, when producing a (meth)acrylic acid ester polymer by the high-temperature continuous polymerization method, molecular weight control can be suitably carried out even when the amounts of the polymerization initiator and the chain transfer agent used are reduced, and the amount of impurities in the curable composition can be minimized as much as possible. Therefore, for the cured product obtained from the curable composition containing the (meth)acrylic acid ester polymer (A), the weather resistance can be made better, and a high-strength molded article can be obtained.

[0073] As the polymerization solvent, an organic solvent can preferably be used. Examples of the organic solvent include cyclic ethers such as tetrahydrofuran and dioxane; chain ethers such as methyl orthoformate and trimethyl orthoacetate; aromatic hydrocarbons such as benzene, toluene, and xylene; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; alcohols such as methanol, ethanol, normal propyl alcohol, isopropyl alcohol, normal butanol, secondary butyl alcohol, isobutyl alcohol, tertiary butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 3-methyl-1-butanol, 1-hexanol, 2-hexanol, 3-methyl-3-pentanol, 1-heptanol, 1-octanol, 2-ethylhexanol, 3-ethyl-3-hexanol, etc.

[0074] The amount of the polymerization solvent used is preferably 5 to 180 parts by mass, more preferably 10 to 150 parts by mass, based on 100 parts by mass of the total amount of the monomers. Note that as the polymerization solvent, one kind can be used alone or two or more kinds can be used in combination.

[0075] As the polymerization initiator, known radical polymerization initiators such as organic peroxides, inorganic peroxides, and azo compounds can be used, and there is no particular limitation.

[0076] Specific examples of the polymerization initiator include, as organic peroxides, for example, di-tert-butyl peroxide, di-tert-hexyl peroxide, cyclohexanone peroxide, dibenzoyl peroxide, 3,3,5-trimethylcyclohexanone peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, etc. As inorganic peroxides, for example, potassium persulfate, sodium persulfate, etc. can be mentioned.

[0077] Examples of azo compounds include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanovaleric acid), 2-(tert-butylazo)-2-cyanopropane, 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2-methylpropane), dimethyl 2,2'-azobis(2-methylpropionate), etc.

[0078] In addition, as the polymerization initiator, a redox type polymerization initiator composed of known oxidizing agents and reducing agents may be used. Examples of the redox type polymerization initiator include those using sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, ferrous sulfate, etc. as reducing agents and potassium peroxodisulfate, hydrogen peroxide, tert-butyl hydroperoxide, etc. as oxidizing agents. Furthermore, a known chain transfer agent can be used in combination with the polymerization initiator. When producing the (meth)acrylic acid ester polymer (A), as the polymerization initiator, an organic peroxide among the above can be preferably used in terms of being easy to control the molecular weight within a desired range.

[0079] When producing the (meth)acrylic acid ester polymer (A), the amount of the polymerization initiator used is, for example, 0.01 to 20 parts by mass, preferably 0.05 to 15 parts by mass, based on 100 parts by mass of the total amount of the monomers used in the polymerization.

[0080] From the viewpoint of controlling the molecular weight of the (meth)acrylic acid ester polymer (A) within the above range and suppressing the coloring of the reaction solution due to the progress of the decomposition reaction, it is preferable to carry out the polymerization at a high temperature. Specifically, the polymerization temperature is preferably within the temperature range of 150°C or higher and 350°C or lower. From the above viewpoint, the polymerization temperature is more preferably 160°C or higher, and still more preferably 180°C or higher. Regarding the upper limit of the polymerization temperature, it is more preferably 330°C or lower, still more preferably 310°C or lower, even more preferably 290°C or lower, and still more preferably 270°C or lower.

[0081] When carrying out the polymerization by the high-temperature continuous polymerization method, the residence time of the raw materials is, for example, 2 to 60 minutes. Also, the pressure during the polymerization may be any pressure that can maintain the polymerization temperature.

[0082] For the polymer obtained by the above polymerization, in order to remove the low-molecular-weight compounds contained in the polymer, isolation and / or purification treatments may be carried out. When carrying out the isolation and / or purification treatments of the polymer, these treatments can be carried out by adopting known methods. For example, the isolation of the polymer can be carried out by thin-film distillation, reprecipitation, or the like.

[0083] <Other Components> Examples of other components to be blended in the present composition include other polymers having a crosslinkable silyl group, plasticizers, fillers, adhesion-imparting agents, dehydrating agents, crosslinking agents (hardening agents), hardening accelerators (hardening catalysts), anti-aging agents, ultraviolet absorbers, and oils.

[0084] · Other polymers having a crosslinkable silyl group Examples of other polymers having a crosslinkable silyl group include polyoxyalkylene polymers having a crosslinkable silyl group, (meth)acrylate polymers having a crosslinkable silyl group and different from the (meth)acrylate polymer (A), polyester polymers having a crosslinkable silyl group, polyurethane polymers having a crosslinkable silyl group, polybutadiene polymers having a crosslinkable silyl group, hydrogenated polybutadiene polymers having a crosslinkable silyl group, and hydrocarbon polymers such as polyisobutylene polymers having a crosslinkable silyl group; and the like. Among these, in terms of excellent mechanical properties of the cured product, it is preferable that this composition contains a polyoxyalkylene polymer having a crosslinkable silyl group together with the (meth)acrylate polymer (A). Examples of the crosslinkable silyl group possessed by the other polymer include the same groups as those exemplified as the crosslinkable silyl group possessed by the (meth)acrylate polymer (A). The crosslinkable silyl group possessed by the other polymer is preferably an alkoxysilyl group in terms of easy control of reactivity.

[0085] Examples of the polyoxyalkylene polymer having a crosslinkable silyl group (hereinafter, also referred to as "polyoxyalkylene polymer (B)") include polymers having a repeating unit represented by the following formula (5). -O-R 5 - …(5) (In formula (5), R 5 represents a divalent hydrocarbon group.)

[0086] Examples of R 5 in the above formula (5) can include the following structures. ·-(CH2) n - (n is an integer from 1 to 10) ·-CH(CH3)CH2- ·-CH(C2H5)CH2- ·-C(CH3)2CH2- The polyoxyalkylene polymer (B) may contain one or a combination of two or more of the above repeating units. Among these, -CH(CH3)CH2- is preferable in terms of excellent workability.

[0087] The method for producing the polyoxyalkylene polymer (B) is not particularly limited. For example, a method of polymerizing using a corresponding epoxy compound or diol compound as a raw material and an alkali catalyst (e.g., KOH, etc.), a method of polymerization using a transition metal compound - porphyrin complex catalyst, a method of polymerization using a composite metal cyanide complex catalyst, a method of polymerization using phosphazene, etc. can be mentioned.

[0088] From the viewpoints of the mechanical properties and adhesiveness of the cured product, the average value of the number of crosslinkable silyl groups contained in one molecule of the polyoxyalkylene polymer (B) is preferably in the range of 1 to 4, more preferably in the range of 1.5 to 3. The position of the crosslinkable silyl group contained in the polyoxyalkylene polymer (B) is not particularly limited and can be the side chain and / or terminal of the polymer. The position of the crosslinkable silyl group contained in the polyoxyalkylene polymer (B) is preferably the polymer terminal. The polyoxyalkylene polymer (B) blended in this composition may be either a linear polymer or a branched polymer. Also, these may be used in combination.

[0089] Regarding the polyoxyalkylene polymer (B), from the viewpoint of mechanical properties, the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 10,000 or more, more preferably 12,000 or more, and still more preferably 15,000 or more. Regarding the upper limit of Mn, from the viewpoint of improving the workability (viscosity) when applying the curable composition, it is preferably 60,000 or less, more preferably 50,000 or less. The range of Mn of the polyoxyalkylene polymer (B) can be set by combining the above upper and lower limit values, but is preferably 10,000 or more and 60,000 or less, more preferably 12,000 or more and 60,000 or less, and still more preferably 15,000 or more and 50,000 or less.

[0090] Regarding the polyoxyalkylene polymer (B), the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 2.5 or less from the viewpoint of obtaining a cured product exhibiting good heat resistance and weather resistance. The molecular weight distribution of the polyoxyalkylene polymer (B) is more preferably 2.2 or less, still more preferably 2.0 or less, and even more preferably 1.8 or less. The lower limit of the molecular weight distribution of the polyoxyalkylene polymer (B) is not particularly limited, but is, for example, 1.1 or more from the viewpoint of ease of production. In the present specification, Mw and Mn of the polyoxyalkylene polymer (B) are polystyrene conversion values measured by gel permeation chromatography (GPC).

[0091] Commercially available products may be used as the polyoxyalkylene polymer (B). Specifically, examples thereof include "MS Polymer S203", "MS Polymer S303", "MS Polymer S810", "Silyl SAX510", "Silyl SAX220", "Silyl SAT200", "Silyl SAT350", "Silyl EST280" and "Silyl SAT30" manufactured by Kaneka Corporation, and "Exesta ES-S2410", "Exesta ES-S2420", "Exesta ES-S3430" and "Exesta ES-S4530" (all are trade names) manufactured by AGC Inc.

[0092] When the composition contains a polyoxyalkylene polymer (B), its content is preferably 1 part by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more with respect to 100 parts by mass of the total amount of the (meth)acrylate polymer (A) and the polyoxyalkylene polymer (B). By setting the content of the polyoxyalkylene polymer (B) within the above range, it is suitable in that a cured product having high mechanical properties can be obtained. Regarding the upper limit of the content of the polyoxyalkylene polymer (B), from the viewpoint of obtaining a cured product exhibiting excellent weather resistance, it is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and still more preferably 60 parts by mass or less with respect to 100 parts by mass of the total amount of the (meth)acrylate polymer (A) and the polyoxyalkylene polymer (B).

[0093] · Plasticizer Examples of the plasticizer include liquid polyurethane resins, polyester plasticizers obtained from dicarboxylic acids and diols; etherified or esterified products of polyalkylene glycols such as polyethylene glycol and polypropylene glycol; polyether plasticizers such as saccharide-based polyethers obtained by subjecting saccharides such as sucrose and polyhydric alcohols to addition polymerization of alkylene oxides such as ethylene oxide and propylene oxide and then etherifying or esterifying; polystyrene-based plasticizers such as poly-α-methylstyrene; poly(meth)acrylates having no crosslinkable silyl group, etc. Among these, poly(meth)acrylates having no crosslinkable silyl group are preferable in terms of the durability such as the weather resistance of the cured product. The plasticizer is preferably a polymer having an Mw in the range of 1,000 to 7,000 and a glass transition temperature of -30°C or lower.

[0094] The amount of the plasticizer used is preferably in the range of 0 to 100 parts by mass, may be in the range of 0 to 80 parts by mass, or may be in the range of 0 to 70 parts by mass with respect to 100 parts by mass of the total amount of the (meth)acrylate polymer (A) and the polyoxyalkylene polymer (B).

[0095] ·Filler Examples of the filler include light calcium carbonate having an average particle size of about 0.02 to 2.0 μm, heavy calcium carbonate having an average particle size of about 1.0 to 5.0 μm, titanium oxide, carbon black, synthetic silicic acid, talc, zeolite, mica, silica, calcined clay, kaolin, bentonite, aluminum hydroxide, barium sulfate, glass balloon, silica balloon, and methyl polymethacrylate balloon. By using these fillers, the mechanical properties of the cured product can be improved, and the tensile strength and elongation at break can be enhanced.

[0096] Among these, as the filler, light calcium carbonate, heavy calcium carbonate, and titanium oxide are preferable in terms of high effect of improving physical properties, and a mixture of light calcium carbonate and heavy calcium carbonate, or a mixture of light calcium carbonate, heavy calcium carbonate, and titanium oxide is more preferable.

[0097] The blending amount of the filler is preferably 20 to 300 parts by mass, more preferably 50 to 200 parts by mass, based on 100 parts by mass of the total amount of the (meth)acrylate polymer (A) and the polyoxyalkylene polymer (B). When using a mixture containing light calcium carbonate and heavy calcium carbonate as the filler, the ratio of light calcium carbonate / heavy calcium carbonate is preferably in the range of 90 / 10 to 50 / 50 by mass.

[0098] ·Adhesion promoter Examples of the adhesion promoter include aminosilanes such as "KBM602", "KBM603", "KBE602", "KBE603", "KBM902", and "KBM903" manufactured by Shin-Etsu Silicone Co., Ltd. Examples of the dehydrating agent include methyl orthoformate, methyl orthoacetate, vinyltrimethoxysilane, and vinylsilane. The blending amount of the adhesion promoter is preferably 0 to 20 parts by mass, more preferably 0 to 10 parts by mass, based on 100 parts by mass of the total amount of the (meth)acrylate polymer (A) and the polyoxyalkylene polymer (B).

[0099] ·Curing agent Examples of the curing agent include epoxy compounds having two or more epoxy groups, isocyanate compounds having two or more isocyanate groups, aziridine compounds having two or more aziridinyl groups, oxazoline compounds having an oxazoline group, metal chelate compounds, butylated melamine compounds, and the like. Among these, epoxy compounds, isocyanate compounds, and aziridine compounds are preferred as the curing agent, and among them, isocyanate compounds are preferred in terms of obtaining a cured product with good physical properties under high-temperature conditions.

[0100] Examples of the epoxy compound include polyfunctional glycidyl compounds such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, tetraglycidyl xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, and sorbitol polyglycidyl ether.

[0101] Examples of the isocyanate compound include various aromatic, aliphatic, and alicyclic isocyanate compounds, as well as modified products (modified isocyanates) of these isocyanate compounds. Examples of the aromatic isocyanate include diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate (NDI), p-phenylene diisocyanate (PPDI), xylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), and tolidine diisocyanate (TODI). Examples of the aliphatic isocyanate include hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), and lysine triisocyanate (LTI). Examples of alicyclic isocyanates include isophorone diisocyanate (IPDI), cyclohexyl diisocyanate (CHDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), and the like. Examples of modified isocyanates include urethane-modified products, dimers, trimers, carbodiimide-modified products, allophanate-modified products, biuret-modified products, urea-modified products, isocyanurate-modified products, oxazolidone-modified products, isocyanate group-terminated prepolymers, and the like of the above isocyanate compounds.

[0102] Examples of aziridine compounds include 1,6-bis(1-aziridinylcarbonylamino)hexane, 1,1'-(methylene-di-p-phenylene)bis-3,3-aziridyl urea, 1,1'-(hexamethylene)bis-3,3-aziridyl urea, ethylene bis-(2-aziridinylpropionate), tris(1-aziridinyl)phosphine oxide, 2,4,6-triaziridinyl-1,3,5-triazine, trimethylolpropane-tris-(2-aziridinylpropionate), and the like.

[0103] The content of the curing agent is 0 parts by mass or more and 10 parts by mass or less with respect to a total of 100 parts by mass of the (meth)acrylate polymer (A) and the polyoxyalkylene polymer (B). The content of the curing agent is preferably 5 parts by mass or less, and more preferably 2 parts by mass or less.

[0104] ·Curing accelerator As the curing accelerator, known compounds such as tin-based catalysts, titanium-based catalysts, and tertiary amines can be used. Among these, examples of tin-based catalysts include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diacetonato, dioctyltin dilaurate, and the like. Specifically, products with the trade names "Neostan U-28", "Neostan U-100", "Neostan U-200", "Neostan U-220H", "Neostan U-303", and "SCAT-24" manufactured by Nitto Kasei Co., Ltd. are exemplified. Examples of the titanium-based catalyst include tetraisopropyl titanate, tetra-n-butyl titanate, titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethylacetylacetonate, dibutoxytitanium diacetylacetonate, diisopropoxytitanium diacetylacetonate, titanium octylene glycolate, titanium lactate, and the like. Examples of the tertiary amines include triethylamine, tributylamine, triethylenediamine, hexamethylenetetramine, 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), diazabicyclononene (DBN), N-methylmorpholine, N-ethylmorpholine, and the like.

[0105] The compounding amount of the curing accelerator is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the total amount of the (meth)acrylate polymer (A) and the polyoxyalkylene polymer (B).

[0106] ·Antioxidant As the antioxidant, ultraviolet absorbers such as benzophenone-based compounds, benzotriazole-based compounds, and oxalic acid anilide-based compounds, light stabilizers such as hindered amine-based compounds, antioxidants such as hindered phenol-based compounds, heat stabilizers, and mixtures thereof can be used. Further, known ones as ultraviolet absorbers can also be used as the antioxidant. Examples of the ultraviolet absorber include products named "Tinuvin 571", "Tinuvin 1130", and "Tinuvin 327" manufactured by BASF. Examples of the light stabilizer include products named "Tinuvin 292", "Tinuvin 144", and "Tinuvin 123" manufactured by BASF, and a product named "Sanol 770" manufactured by Sankyo. Examples of the heat stabilizer include products named "Irganox 1135", "Irganox 1520", and "Irganox 1330" manufactured by BASF. Further, a product named "Tinuvin B75" manufactured by BASF, which is a mixture of an ultraviolet absorber / light stabilizer / heat stabilizer, may be used.

[0107] The blending amount of the anti-aging agent is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the total amount of the (meth)acrylate polymer (A) and the polyoxyalkylene polymer (B).

[0108] Examples of other components that may be blended in the present composition include, in addition to the above, dehydrating agents, coloring agents, etc. Further, for the purpose of adjusting the performance, coatability, processability, etc. of the curable composition containing the (meth)acrylate polymer (A), other thermoplastic resins, etc. may be blended in the present composition. Specific examples of the thermoplastic resin include polyolefin resins such as polyethylene and polypropylene; styrene resins such as polystyrene; vinyl resins such as polyvinyl chloride; polyester resins; polyamide resins, etc. Also, known elastomers may be blended within a range not impairing the effects of the present invention.

[0109] The present composition may be used as a one-component curable resin composition in which all the blended components are pre-blended and sealed for storage, and after opening and applying during use, the present composition cures by absorbing moisture in the air. Further, as a curing agent, components such as a curing catalyst, a filler, and a plasticizer are separately blended, and during use, the present composition can also be used as a two-component curable resin composition in which the components containing the curing agent and the present composition are mixed.

[0110] The present composition containing the (meth)acrylate polymer (A) exhibits good fluidity in the temperature range of room temperature (25°C) to about 150°C. Therefore, in addition to coating by various methods, a cured product can be manufactured by adopting various molding processes such as extrusion molding, injection molding, and casting molding. In particular, the present composition can be easily cured at a sufficient rate by moisture in the air, etc., preferably by blending or adding a curing accelerator. Such a present composition is useful as a sealing material, an adhesive, a paint, a coating agent, a molding material, a rubber sheet, etc. in various fields such as the construction field, the civil engineering field, the electric and electronic field, and the automotive field. Considering that the (meth)acrylate polymer (A) has high elongation and is excellent in heat resistance and weather resistance, the present composition containing the (meth)acrylate polymer (A) is suitable for applications such as sealing materials, adhesives, adhesives, and paints, and is particularly suitable as a sealing material (i.e., a sealing material composition).

Examples

[0111] Hereinafter, the present disclosure will be specifically described based on examples, but the present disclosure is not limited by these examples. In the following, "parts" and "%" mean "parts by mass" and "mass%" respectively unless otherwise specified. The details of the analysis methods of the polymers obtained in the synthesis examples and comparative synthesis examples are as follows.

[0112] ≪Analysis Method of Polymer≫ <Measurement of Molecular Weight> Using a gel permeation chromatograph device (model name "HLC-8320", manufactured by Tosoh Corporation), the weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of polystyrene were obtained under the following conditions. ○Measurement Conditions Column: 4 TSKgel SuperMultipore HZ-M columns manufactured by Tosoh Corporation Column Temperature: 40°C Eluent: Tetrahydrofuran Detector: RI

[0113] <Measurement of Viscosity> Using a TVE-20H viscometer (cone / plate type, manufactured by Toki Sangyo Co., Ltd.), the E-type viscosity was measured under the following conditions. ○ Measurement conditions Cone shape: Angle 1°34′, radius 24 mm (less than 10 Pa·s) Angle 3°, radius 7.7 mm (10 Pa·s or more) Temperature: 25 °C ± 0.5 °C

[0114] <Average number of crosslinkable silyl groups in the (meth)acrylate polymer> The number (average number) f(Si) of crosslinkable silyl groups was calculated by the following formula (6) from the amount (parts by mass) of the monomer having a crosslinkable silyl group (specifically, an alkoxysilyl group) (hereinafter also referred to as "silyl group monomer") when the total amount of the monomers used in the synthesis of the (meth)acrylate polymer was 100 parts by mass. f(Si) = {parts by mass of silyl group monomer / (molecular weight of silyl group monomer × 100 / Mn)} …(6)

[0115] <Crosslinkable silyl group ratio> The crosslinkable silyl group ratio was calculated by the following formula (7) to obtain the number (average number) f(S2) of silyl groups (S2) from the amount (parts by mass) of the silyl group monomer having a silyl group (S2) when the total amount of the monomers used in the synthesis of the (meth)acrylate polymer was 100 parts by mass, and was calculated by the following formula (7) using the calculated f(S2) and f(Si). f(S2) = {parts by mass of silyl group monomer having silyl group (S2) / (molecular weight of silyl group monomer having silyl group (S2) × 100 / Mn)} …(7) Crosslinkable silyl group ratio = f(S2) / f(Si) …(7)

[0116] <Glass transition temperature (Tg)> It was determined by calculation according to the above formula (4).

[0117] 1. Synthesis of (meth)acrylate polymer (Synthesis Example 1) Synthesis of Polymer 1 The temperature of a 1000 mL pressure - stirred tank reactor equipped with an oil jacket was maintained at 191°C. Then, while keeping the pressure of the reactor constant, 74.2 parts of n - butyl acrylate (hereinafter referred to as "BA"), 20 parts of 2 - ethylhexyl acrylate (hereinafter referred to as "HA"), 3 parts of methyl methacrylate (hereinafter referred to as "MMA"), 3 - methacryloxypropyltrimethoxysilane (hereinafter referred to as "TMS"), 3 - methacryloxypropylmethyldimethoxysilane (hereinafter referred to as "DMS"), 4 parts of isopropyl alcohol (hereinafter referred to as "IPA"), 4 parts of trimethyl orthoacetate (hereinafter referred to as "MOA"), 6 parts of methyl ethyl ketone (hereinafter referred to as "MEK"), and 0.5 part of di - t - hexyl peroxide (manufactured by NOF Corporation, trade name "Perhexy H", hereinafter referred to as "DTHP") as a polymerization initiator were continuously fed from the raw material tank into the reactor at a constant supply rate (48 g / min) to start the polymerization reaction with a residence time of 12 minutes. Then, the reaction solution corresponding to the supply amount of the monomer mixture was continuously withdrawn and recovered from the outlet of the reactor. Immediately after the start of the reaction, although the reaction temperature decreased once, a temperature increase due to the heat of polymerization was observed. Therefore, by controlling the temperature of the oil jacket, the reaction temperature was maintained at 190 - 192°C (in Table 1, the intermediate temperature of 191°C is described). The point when the liquid temperature in the reactor became stable after the start of the supply of the monomer mixture was set as the starting point for collecting the reaction solution, and the reaction was carried out for 25 minutes from the starting point of collection. As a result, the supply amount of the monomer mixture was 1.2 kg, and the recovery amount of the reaction solution was 1.2 kg. The mixed solution of the polymer, solvent, and unreacted monomer coming out of the reactor was continuously introduced into a thin - film evaporator to separate volatile components such as unreacted monomers, and 0.97 kg of Polymer 1 was obtained.

[0118] (Synthesis Examples 2 - 17 and Comparative Synthesis Examples 1 - 6) Synthesis of Polymers 2 - 23 Polymers 2 - 23 were obtained in the same manner as in Production Example 1, except that the types and amounts of raw materials were changed as shown in Table 1. In Table 1, the units of the numerical values of the monomers, solvents, and polymerization initiators are parts by mass.

[0119]

Table 1

[0120] In Table 1, the abbreviations of the monomers and solvents are as follows. (Monomer) MMA: Methyl methacrylate TDA: Tetradecyl acrylate HA: 2-Ethylhexyl acrylate BA: n-Butyl acrylate TMS: 3-Methacryloxypropyltrimethoxysilane DMS: 3-Methacryloxypropylmethyldimethoxysilane (Solvent) IPA: Isopropyl alcohol MOA: Trimethyl orthoacetate MEK: Methyl ethyl ketone

[0121] 2. Production of the curable composition According to the mixing ratios shown in Table 2 and Table 3, each component was mixed, and curable compositions of Examples 1 to 17 and Comparative Examples 1 to 6 were obtained according to a conventional method. The details of the compounds in Table 2 and Table 3 are as follows. · ES-S4530: Polyoxyalkylene polymer (B), modified silicone ester ES-S4530 (manufactured by AGC Inc.) · UP-1020: Plasticizer, acrylic plasticizer, ARUFON (registered trademark) UP-1020 (manufactured by Toagosei Co., Ltd.) · CCR: Light calcium carbonate, Hakuenka CCR (manufactured by Shiraishi Calcium Co., Ltd.) · SS: Heavy calcium carbonate, Super SS (manufactured by Maruo Calcium Co., Ltd.) · R-820: Titanium oxide, product name "R-820" (manufactured by Ishihara Sangyo Co., Ltd.) · B75: Antioxidant, product name "Tinuvin B75" (manufactured by Ciba Specialty Chemicals Inc.) · U-220H: Tin catalyst (dibutyltin diacetylacetonate), product name "Neostan U-220H" (manufactured by Nitto Kasei Co., Ltd.)

[0122] 3. Evaluation of the curable composition For each of the curable compositions of Examples 1 to 17 and Comparative Examples 1 to 6, the following evaluations were carried out. The evaluation results are shown in Tables 2 and 3. (1) Tensile properties Each curable composition was applied to a Teflon (registered trademark) sheet at a thickness of 2 mm at room temperature (25 °C), and cured sheets were prepared by curing for 5 days under the conditions of 23 °C and 50% RH (relative humidity), and then for 1 day in a saturated steam atmosphere at 50 °C. Dogbones for tensile testing were prepared from the obtained cured sheets, and the tensile properties were measured using a tensile testing machine (Autograph AGS-J, manufactured by Shimadzu Corporation). The shape of the dogbone for tensile testing is based on No. 3 of JIS K 6251, which is a Japanese Industrial Standard. Specifically, under the conditions of a tensile speed of 200 mm / min in an environment of 23 °C and 50% humidity, the strength at 50% elongation (M50, unit: MPa), the strength at break (Ts, unit: MPa), and the elongation at break (El, unit: %) were measured.

[0123] (2) Heat resistance The above dogbones for tensile testing were placed in an 80 °C dryer and heated for 2 weeks, and then cured for 1 day under the conditions of 23 °C and 50% RH (relative humidity). Then, using a tensile testing machine (Autograph AGS-J, manufactured by Shimadzu Corporation), a tensile test was carried out at a tensile speed of 200 mm / min, and the strength at 50% elongation (M50, unit: MPa), the strength at break (Ts, unit: MPa), and the elongation at break (El, unit: %) were measured. In addition, the value obtained by dividing the elongation at break (El) after heat treatment by the dryer at 80 °C by the elongation at break (El) measured before heat treatment in the above (1) was defined as the elongation retention rate (unit: %), and the heat resistance of the cured sheet was evaluated based on the elongation retention rate and the elongation at break (El) after heat treatment. It can be evaluated that the higher the elongation retention rate and the larger the value of the elongation at break after heat treatment, the better the heat resistance. Specifically, if the elongation retention rate is 70% or more and the elongation at break after heat treatment is 300% or more, the cured sheet can be evaluated as having practicality. The heat resistance was evaluated according to the following criteria. ◎: The elongation retention rate is 80% or more, and the elongation at break after heat treatment is 500% or more ○: Elongation retention rate is 70% or more, and the elongation at break after heat treatment is 300% or more △: Elongation retention rate is 60% or more, and the elongation at break after heat treatment is 300% or more ×: Elongation at break after heat treatment is less than 300%

[0124] (3) Workability Each curable composition was applied to a substrate with a spatula, and the ease of application (workability) of each curable composition was evaluated according to the following criteria. ◎: Very good ○: Good △: Fair ×: Poor

[0125] (4) Compatibility ES-S4530 (manufactured by AGC, polyoxyalkylene polymer (B)) and a (meth)acrylate polymer having a crosslinkable silyl group were mixed and stirred at a weight ratio of 1:1, then transferred to a glass bottle, purged with nitrogen, and sealed. After leaving it overnight in an environment of 23 °C and 50% RH (relative humidity), the state of the liquid was observed and evaluated according to the following criteria. ○: Good (the liquid is transparent and not separated) △: Fair (no separation of the liquid occurs, but it is slightly opaque) ×: Poor (the liquid is separated or turbid)

[0126] (5) Weather resistance Each curable composition was applied to a Teflon (registered trademark) sheet with a thickness of 2 mm at room temperature (25 °C), and cured sheets were prepared by curing for 5 days under the conditions of 23 °C and 50% RH (relative humidity), and then for 1 day in a saturated steam atmosphere at 50 °C. The obtained cured sheet was placed in a metal weather meter (manufactured by Daipra Wintersteiger Co., Ltd., "DAIPLA M ETAL WEATHER KU-R5NCI-A"), and an accelerated weather resistance test was conducted. The conditions were irradiation at 63 °C, 70% RH (relative humidity), and illuminance of 80 mW / cm 2 and the test was carried out with a 2-minute shower once every 2 hours. Samples were taken out 600 hours and 900 hours after the start of the test, the surface of the cured sheet was observed, and each was evaluated according to the following criteria. ○: Good (No appearance abnormalities such as cracks or bleed are observed.) △: Fair (Appearance abnormalities such as cracks or bleed are observed in a part of the surface of the cured product.) ×: Poor (Appearance abnormalities such as cracks or bleed are observed over the entire surface of the cured product.)

[0127]

Table 2

[0128]

Table 3

[0129] 4. Evaluation Results As is clear from the results in Table 2 and Table 3, the (meth)acrylate polymer used in Examples 1 to 17 had good compatibility with the polyoxyalkylene polymer (B) and also had good workability. Further, according to the curable compositions of Examples 1 to 17, cured sheets excellent in initial tensile properties, heat resistance, and weather resistance could be obtained.

[0130] On the other hand, Comparative Example 1 and Comparative Example 2 in which the number of crosslinkable silyl groups f(Si) of the (meth)acrylate polymer is more than 0.5, Comparative Example 3 in which the number of crosslinkable silyl groups f(Si) of the (meth)acrylate polymer is less than 0.2, the number of crosslinkable silyl groups f(Si) is equivalent to that of Examples 1 to 17 but the crosslinkable silyl group ratio is less than 0.3 (that is, the ratio of silyl group (S2) is small) Comparative Example 4, Comparative Example 5 in which the SP value of the (meth)acrylate polymer is less than 9.4, and Comparative Example 6 in which the Mw of the (meth)acrylate polymer exceeds 30,000. The cured sheets produced in any of these cases had an elongation retention rate upon heat application lower than that of Examples 1 to 17 and were inferior in heat resistance. Furthermore, the cured sheets obtained in Comparative Examples 2 to 5 were also inferior in weather resistance to Examples 1 to 17, and Comparative Example 6 was inferior in workability to Examples 1 to 17.

Claims

1. containing a (meth)acrylic acid ester polymer (A) having a crosslinkable silyl group, the (meth)acrylic acid ester polymer (A) has a weight average molecular weight of 5,000 or more and 30,000 or less, and the following formula (1): -SiX １ X ２ X ３ …(1) (In formula (1), X １ , X ２ and X ３ are each independently a hydroxyl group or a hydrolyzable group.) a silyl group (S1) represented by, and the following formula (2): -SiR １ X ４ X ５ …(2) (In formula (2), R １ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, or -OSiR ２ R ３ R ４ (However, R ２ , R ３ and R ４ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms.) and one or more hydrogen atoms may be substituted. X ４ and X ５ are each independently a hydroxyl group or a hydrolyzable group.) the total average number of the silyl group (S2) represented by in one molecule is 0.20 or more and less than 0.50, and the ratio of the number of the silyl group (S2) to the total number of the silyl group (S1) and the silyl group (S2) in one molecule is 0.3 or more and 1.0 or less, and the SP value is 9.4 or more and 9.8 or less, a curable composition.

2. the (meth)acrylic acid ester polymer (A) includes a structural unit derived from an acrylic acid ester compound (a) in which the residue excluding -COO- in the ester group is linear or branched with 1 to 4 carbon atoms, and a structural unit derived from an acrylic acid ester compound (b) in which the residue excluding -COO- in the ester group is linear or branched with 8 to 22 carbon atoms, and optionally includes a structural unit derived from a methacrylic acid ester compound (c) in which the residue excluding -COO- in the ester group is linear or branched with 1 to 4 carbon atoms, based on the total amount of the structural units derived from the monomers constituting the (meth)acrylic acid ester polymer (A), the proportion of the structural unit derived from the acrylic acid ester compound (a) is 50% by mass or more and 95% by mass or less, the proportion of the structural unit derived from the acrylic acid ester compound (b) is 10% by mass or more and 40% by mass or less, and the proportion of the structural unit derived from the methacrylic acid ester compound (c) is 0% by mass or more and 10% by mass or less, the curable composition according to Claim 1.

3. the viscosity of the (meth)acrylic acid ester polymer (A) measured at 25 °C with an E-type viscometer is 1 Pa·s or more and 20 Pa·s or less, the curable composition according to Claim 1 or 2.

4. further containing a polyoxyalkylene polymer having a crosslinkable silyl group, the curable composition according to Claim 1 or 2.

5. the glass transition temperature of the (meth)acrylic acid ester polymer (A) is -15 °C or lower, the curable composition according to Claim 1 or 2.

6. being for a sealing material, the curable composition according to Claim 1 or 2.

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